Parents of Georgia teen who died in 'freak accident' believe son was murdered

The parents of a Georgia teenager, whose body was found inside a rolled-up wrestling mat in his high school gym, believe their son was murdered, the family's attorney said Thursday.

Kendrick Johnson, of Valdosta, Ga., was found Jan. 11 stuck in an upright mat propped behind the bleachers inside his high school gym. Lowndes County sheriff's investigators concluded Johnson died in a freak accident, but the 17-year-old's family disputes that.

"They never believed he died the way the sheriff concluded. They believe that it defies logic, the laws of physics as well as common sense," Crump said. "They think this is a cover-up to protect the person or people responsible for their son’s death."

"They sent their son to school with a book-bag and he was returned to them in a body bag," he said.

U.S. Attorney Michael Moore said Thursday he is conducting a formal investigation into Johnson's death, noting that several key questions remain unanswered.

"What was the cause of death? Was his death the result of a crime?" Moore said at a press conference Thursday afternoon. "I will follow the facts wherever they lead. My objective is to discovery the truth."

"I am of the opinion that a sufficient basis exists" for a formal investigation, he said.

Moore told reporters that the initial autopsy indicated Johnson died as a result of "positional asphyxia." A second autopsy, however, listed a different cause of death, according to Moore.

"There are several questions that must be answered or confirmed," he said.

Moore added that if he uncovers sufficient evidence to warrant a criminal or civil rights investigation into the death of Johnson he will ask the FBI to conduct it.

A representative from the Lowndes County Sheriff's Office was not immediately available for comment when contacted Thursday.

A southern Georgia judge on Wednesday ordered authorities to release all surveillance video that investigators reviewed. The teenager's parents said they hope the video footage will contain clues to how he died.

FoxNews.com's Cristina Corbin and the Associated Press contributed to this report.